Released
Dataset

The South American gravimetric quasi-geoid: QGEOID2021

Cite as:

de Matos, Ana Cristina Oliveira Cancoro; Blitzkow, Denizar; Guimarães, Gabriel do Nascimento; Silva, Valéria Cristina (2021): The South American gravimetric quasi-geoid: QGEOID2021. V. 1.0. GFZ Data Services. https://doi.org/10.5880/isg.2021.005

Status

I   N       R   E   V   I   E   W : de Matos, Ana Cristina Oliveira Cancoro; Blitzkow, Denizar; Guimarães, Gabriel do Nascimento; Silva, Valéria Cristina (2021): The South American gravimetric quasi-geoid: QGEOID2021. V. 1.0. GFZ Data Services. https://doi.org/10.5880/isg.2021.005

Abstract

The South American gravimetric quasi-geoid model, named QGEOID2021, was computed thanks to a collaboration of several institutions, companies and universities of South America. The model covers the area between 15°N and 60°S in latitude and 100°W and 30°W in longitude, with a grid resolution of 5' x 5'. It is based on 959,404 terrestrial gravimetric points, the XGM2019 global geopotential model up to degree and order 200 and the SRTMv3 digital terrain model. The short wavelengths of the solution were estimated via Fast Fourier Transform (FFT) with the modified Stokes kernel proposed by Vaníček and Kleusberg (1987). On the other hand, long and medium wavelengths were removed and replaced in the framework of a remove-compute-restore procedure. Regions without gravimetric observations were completed using XGM2019 to its full degree. The calculation of the geoid model was performed by the Canadian package SHGEO (Stokes-Helmert Geoid Software). The quasi-geoid model was obtained by the classical geoid/quasi-geoid separation term (Heiskanen and Moritz, 1967). The comparison between height anomalies and GPS/levelling data at 1108 points in Brazil shows differences with an RMS of 41 cm.

The geoid model is provided in ISG format 2.0 (ISG Format Specifications), while the file in its original data format is available at the model ISG webpage.

Additional Information

The International Service for the Geoid (ISG) was founded in 1992 (as International Geoid Service - IGeS) and it is now an official service of the International Association of Geodesy (IAG), under the umbrella of the International Gravity Field Service (IGFS). The main activities of ISG consist in collecting, analysing and redistributing local and regional geoid models, as well as organizing international schools on the geoid determination (Reguzzoni et al., 2021).

Authors

Contact

Contributors

Reguzzoni, Mirko; Carrion, Daniela; Rossi, Lorenzo; ISG Staff

Keywords

Geodesy, Geoid model, ISG, Fast Fourier Transform, South America

GCMD Science Keywords

Location

Please, click on markers, line , bounding boxes or the list below to see related details in popup.
To explore to full geographic extent of the map please click and drag the map.

    Files

    License: CC BY 4.0

    Dataset Description

    Documented by

    Related Work

    Variant Form of

    References